diff --git a/include/mcl/gmp_util.hpp b/include/mcl/gmp_util.hpp
index 8befc1d..63c8f77 100644
--- a/include/mcl/gmp_util.hpp
+++ b/include/mcl/gmp_util.hpp
@@ -710,7 +710,7 @@ public:
 		s = 0;
 		q_add_1_div_2 = 0;
 	}
-#ifndef CYBOZU_DONT_USE_USE_STRING
+#if !defined(CYBOZU_DONT_USE_USE_STRING) && !defined(CYBOZU_DONT_USE_EXCEPTION)
 	void dump() const
 	{
 		printf("\"%s\",\n", mcl::gmp::getStr(p, 16).c_str());